Emulating a line-based interrupt transaction in response to a message signaled interrupt

• US 7,979,619 B2
• Filed: 12/23/2008
• Issued: 07/12/2011
• Est. Priority Date: 12/23/2008
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Company (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Laue, Matthew Ryan, Barde, Kaushik, Bramley, Richard
• Primary Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US12/317,646
• Publication Number:
  US 20100161864A1
• Time in Patent Office: 931 Days
• Field of Search: 710260-269, 710 48- 50
• US Class Current: 710/261
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors

Abstract

Methods, systems, apparatuses and program products are disclosed for managing interrupt services in hypervisor and hypervisor-related environments in Message Signaled Interrupts are emulated as other type(s) of interrupt.

According to an aspect of the present invention, a method of executing a program includes receiving a MSI (message signaled interrupt). Responsively, a virtual interrupt is generated and an ISR (interrupt service routine) is invoked that handles a line-based virtual interrupt transaction. A surrogate or virtual peripheral device status may also be provided and may be associated with the virtual interrupt. A single device interrupt event may, in certain circumstances, be serviced both as a line-based interrupt and also as an MSI, or as either responsive to run-time context.

Embodiments of the present invention enable superior tradeoffs in regards to the interrupt sharing to a greater and more flexible extent than with previous implementations. Moreover, it makes possible interrupt sharing using an ISR that was not expressly designed for interrupt sharing.

Claims

1. A method of executing a program comprising:

receiving a message signaled interrupt associated with a peripheral device by a first interrupt service routine in a privileged domain;

calling a second interrupt service routine in a non-privileged domain responsive to receiving the message signaled interrupt;

emulating a line-based interrupt transaction into the second interrupt service routine;

trapping, by a hypervisor in the privileged domain, input/output (I/O) functions invoked by the second interrupt service routine; and

performing, by the hypervisor, virtualized I/Os by emulating the peripheral device associated with the message signaled interrupt.

2. The method of claim 1 wherein:

the first interrupt service routine runs in a more privileged processor mode; and

the second interrupt service routine runs in a less privileged processor mode.

3. The method of claim 1 wherein:

the first interrupt service routine is associated with a hypervisor program that runs in a privileged domain; and

the second interrupt service routine is associated with an operating system program.

4. The method of claim 3 wherein the step of:

emulating is performed by service routines that provide a virtualized sharing of the peripheral device.

5. The method of claim 3 wherein:

the second interrupt service routine is shared by multiple interrupt-capable virtual devices.

6. The method of claim 4 wherein:

the virtualized sharing provides a surrogate peripheral device status to the second interrupt service routine; and

the privileged domain processes input-output data to or from the peripheral device.

7. A computer program product comprising:

at least one computer-readable medium having instructions encoded therein, the instructions when executed by at least one processor cause said at least one processor to;

operate for interrupt handling by steps comprising the acts of;

receiving a message signaled interrupt associated with a peripheral device by a first interrupt service routine in a privileged domain;

calling a second interrupt service routine in a non-privileged domain responsive to receiving the message signaled interrupt;

emulating a line-based interrupt transaction into the second interrupt service routine;

trapping, by a hypervisor in the privileged domain, input/output (I/O) functions invoked by the second interrupt service routine; and

performing, by the hypervisor, virtualized I/Os by emulating the peripheral device associated with the message signaled interrupt.

8. The computer program product of claim 7 wherein:

the first interrupt service routine runs in a more privileged processor mode; and

the second interrupt service routine runs in a less privileged processor mode.

9. The computer program product of claim 7 wherein the emulating is performed by service routines that provide a virtualized sharing of the peripheral device.

10. A method comprising:

an act of modulating a signal onto an electro-magnetic carrier wave impressed into a tangible medium, or of demodulating the signal from the electro-magnetic carrier wave, the signal having instructions encoded therein, the instructions when executed by at least one processor causing said at least one processor to;

operate for interrupt handling by steps comprising the acts of;

receiving a message signaled interrupt associated with a peripheral device by a first interrupt service routine in a privileged domain;

calling a second interrupt service routine in a non-privileged domain responsive to receiving the message signaled interrupt;

emulating a line-based interrupt transaction into the second interrupt service routine;

trapping, by a hypervisor in the privileged domain, input/output (I/O) functions invoked by the second interrupt service routine; and

performing, by the hypervisor, virtualized I/Os by emulating the peripheral device associated with the message signaled interrupt.

11. The method of claim 10 wherein:

the first interrupt service routine runs in a more privileged processor mode; and

the second interrupt service routine runs in a less privileged processor mode.

12. The method of claim 10 wherein the emulating is performed by service routines that provide a virtualized sharing of the peripheral device.